A single credit card relationship between a credit card issuer and a member can be very long-lived. As a result, the relationship can include many different account numbers over time. For example, a new card with a new number can be issued if the card is lost, stolen, the member changes the card type (Standard, Gold or Platinum), or the card number is thought to be compromised. Sometimes, data security compromises committed by third-parties can result in a simultaneous mass re-issue of many cards.
Unfortunately, historic credit card data can contain inconsistent and erroneous relationships between credit card accounts and their predecessors and successors. The problem is compounded by the fact that historic relationships are only available as monthly snapshots, and there is no clear way to tell exactly when a card was issued, because the issue dates are only accurate within about 10 days, and not necessarily in the correct order. This creates the need for ways to identify and track the account throughout its life.